1. Use a furnace calculator, such as HVAC Equipment Size Finder, Home Heat Loss Calculator or the Energy Star Furnace Calculator, to determine the amount of BTUs needed for your home
http://www.ehow.com/how_8649560_calculatefurnace...

1. Check a list of recorded values to find the insulation's resistivity. For example, if the cable uses Teflon insulation, note that it has a resistivity of 1 × 10^19 ohmmeters
http://www.ehow.com/how_12060178_calculateinsulat...

1. Measure the length of the ladder with a measuring tape when it is fully closed. This tells you how long the ladder will be when it's being carried by people or atop a work truck.
http://www.ehow.com/how_7169830_calculateextensio...

1. Place your socked foot on a sheet of 8by11inch paper on the ground. If your foot is too long to fit lengthwise, step on the page diagonally. If your foot is still too long,
http://www.ehow.com/how_6661077_calculatesizespo...
